(i) Technical Field
The present invention relates to a developer transport device, a developing device, a visible image forming device, and an image forming apparatus.
(ii) Related Art
In an image forming apparatus in the related art, such as electrophotographic copiers and printers, image formation is performed in such a manner that a developer holding body is opposed to a photoreceptor body on whose surface a latent image is formed and the latent image is visualized with a developer that is carried by the surface of the developer holding body.
For example, a two-component developer containing a toner and a carrier is used as the developer. The two-component developer is agitated until it is transported to the developer holding body, whereby lumps of toner are broken up and the tuner and the carrier are charged through friction.
The developer is consumed by image formation and hence requires supply. Furthermore, the developer holding body and the photoreceptor body are deteriorated as they are used, and hence need to be replaced when they have been used for a certain length of time. Therefore, in the image forming apparatus, a developer supply container (what is called a toner cartridge) is made replaceable (detachable) to supply only a developer, the developing device and the photoreceptor body are made replaceable, or the developer supply container and the developing device are integrated with each other so as to be replaced together. These measures are employed widely. In general, such a replaceable developing device is sealed so as to prevent the developer from leaking during storage or transport. When used, such a replaceable developing device is unsealed so as to be rendered usable by causing the developer to flow into the developing device.